Patterns of age and growth in young-of-year rockfish, sebastes spp., along the Oregon coast

Abstract:

Rockfish of the genus Sebastes are important components of Oregon reef communities. I examined patterns of age and growth in young-of-year rockfish across two nested spatial scales – local and regional – along the Oregon coast. Using otolith microstructural examination, I examined the relative importance of local versus regional factors for larval and juvenile growth and development; I investigated the effects of larval growth and development on juvenile growth; and I tested predictions of two hypotheses: the Single Process Concept and the Growth-Mortality Hypothesis. My results suggest that larval growth rates varied on a regional spatial scale, whereas juvenile growth rates varied on a local spatial scale. I found that faster growing larvae metamorphosed at younger ages, corroborating a prediction of the Single Process Concept. Larval growth rates exhibited a negative effect on juvenile growth rates, signifying a trade-off in growth between larval and juvenile stages. There was no evidence of directional growth-selective mortality during the juvenile stage, disproving the Growth-Mortality Hypothesis. Future research should involve long-term studies that focus on temporal patterns of growth and recruitment in young-of-year rockfish across multiple spatial scales, in relation to variability in habitat, biological interactions, and oceanographic conditions.